Carrier Bearing shimming

I am switching from the F250 rear blocks to the F350 blocks as part of my RSK conversion. I am wondering if while not necessary, would it be adviseable to shim the carrier bearing a little. Does anyone know if for say the carrier bearing bracket on a F250 is different then on a F350? For instance is does the F350 carrier sit just a little lower then the F250. I started reading some stuff on pinion angles to do but it did not all sink in. I need to go back and so some more research on all this. I noticed Brad used angled blocks when he did his but the stock blocks are not angled. I am hoping to generate some discussion.

While researching I came across these two 2007 vintage posts from two guys with 97 and 95 trucks.

DIESELDUTTON said:

I replaced my stock blocks with stock 350 non tapered blocks and shimmed the carrier bearing down 3\4 and it was perfect, no vibration. Everyone that I talked to said with my truck and the two piece driveshaft you dont need tapered blocks. My 350 blocks were 4 1/4". Good Luck

Frank

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radarman said:

What he said ^^^^^.

"carrier bearing down 3\4 "

spot on!

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crickets, crickets

Don't know if this helps or not, or if it's even relevant but from where the bracket mounts to the top of the bearing carrier is 7 1/8", total from where it mounts is 12" to bottom of carrier bearing itself on driveshaft. ECLB F350 with stock blocks in the back, there are no spacers or anything on it.

I will have to do some measuring on mine when I get home from a little trip to Gunnison. My prediction is that the F350 will have it mounted a tad lower. I wish I could find a good guide for understanding this.

Tom I can measure mine sometime but I have no shims & the new one didn't come with any. 97 CCLB 4x4 with 4" block on the rear.

A measurement would be much appreciated. I have been doing a bunch of searching for info on this but have not found the right guide to school me up.

There is some interesting info in this Spicer publication on driveline angles I came across.

Just moving a couple inches is going to have very little effect on drive line angle. Pinion angle is important but you're not going to change stuff that much. If you were going with a huge lift, I'd worry about it.

If you're concerned, just check your pinion angle before you start. If it's WAY different after the blocks, get some angled blocks and drop the carrier bearing. Would not be hard to shim that down a bit.

I always had take off shudder on mine. I played with shims and it didn't help. What solved it was a 1 piece driveshaft with a CV joint by the xfer case.:joy:

Billy T.
[email protected]

I currently have no shudder and did not before the traction bars. Sooo I just do not want to aquire any.

Tom

I went from stock F350 blocks (on an F350) to Superduty 5" Lift Springs with no blocks, which netted 2-3" over stock height, similar to what would happen with F250 to F350 blocks. After the new springs I had a shudder on take off (5-10mph or so). I spaced the carrier bearing down 3/4" and the shudder disappeared.

Not exactly your situation but take it for what its worth. Its cheap and easy to try, i think it cost me a whole $10 for the longer bolts and some 1/4" steel stock. The good thing about using 1/4" stock is you can add/remove shims until you get it just right.